JPS606364A - Measuring device for torque - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a 1-to-luke measuring device used to measure the torque of various power tools such as electric screwdrivers.

BACKGROUND ART Conventionally, this type of torque measuring device (U) mainly uses an analog type (herc detection element such as a strain gauge) to measure torque with an analog type peak hold circuit, and converts this torque into a digital signal using a △/D converter. After conversion, the display shows 1.

However, when using an analog-type torque detection element such as a strain gauge, the characteristics change depending on the mounting aspect, so care must be taken when assembling the measuring device. Because the grooves become complicated, the equipment must be installed at a high level.
~． If an all-log type peak hold circuit is used in conjunction with the lux detection element, the charge stored in the peak hold capacitor will be discharged before the display stage, making it impossible to accurately display 1 to lux.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a 1 to 1 torque measuring device that is structurally simple, inexpensive, and capable of accurately displaying torque on soil that is easy to assemble.

The present invention rotates a rotating member in proportion to the torque of an electric screwdriver or the like until it is balanced by the torque between 1 and 2, converts this rotation angle into two pulse signals using a pulse encoder, and converts these rotation angles into two pulse signals. A signal is output with a phase difference that corresponds to forward rotation and nine reverse rotations of an electric screwdriver, etc., and a digital peak hold circuit determines the forward rotation and reverse rotation, and the maximum rotation angle corresponding to the maximum rotation angle during forward rotation of the pulse signal is output. The present invention is characterized in that the number of pulses is bolded, the torque is calculated from this maximum number of pulses by a calculating means, and the value is displayed.

According to the present invention, assembly and structure are simple;
An inexpensive torque measuring device capable of accurately displaying torque is now available.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1(a) is an explanatory diagram of the main part configuration of a torque measuring device according to the present invention, and FIG. 1(b) is a diagram of its circuit configuration. The torque measuring device of the present invention includes an electric screwdriver 1 as an electric tool.
A rotating circuit consisting of a pulse encoder 3 coaxially connected to the pulse encoder via a connector 2, a pulley 4 coaxially fixed to the shaft of the pulse encoder, and a helical spring 5 applying elastic force to the pulley 4. A moving member 6 is provided. The pulse encoder 3 rotates together with the pulley 4 by the torque of the driver 1. Since one end of the helical spring 5 is attached to the pulley 4, when the elastic force of the spring 5 and the torque of 1 to 1 are balanced, the Rotation stops. Therefore, the torque of the driver 1 can be expressed by the rotation angle of the pulley 4, that is, the rotation angle of the pulse encoder 3. As the pulse encoder 3 rotates, it outputs pulse generators (△) and (B) that have a phase difference of 90° corresponding to the rotation angle, but if, for example, a photoelectric element (not shown) shifts its position slightly, Therefore, when driver 1 rotates forward, one pulse signal (
When the phase of A) advances and reverses, the other pulse signal (B)
phase advances (see Figure 2). These pulse signals (Δ) and (B) having different phases are input to the direction discriminator 8 of the digital peak hold circuit 7.

The digital peak hold circuit 7 includes the direction discriminator 8
Up/down counter 9 connected to the output side of
A latch 10 connected to the output side of this counter,
A comparator 11 whose comparison inputs are connected between the counter 9 and the wrap-10 and to the output side of the latch 10, respectively.
and a latch (timing) pulse generator 12 connected to the output of this comparator 11. The direction discriminator 8 determines whether the driver 1 rotates in the normal direction or in the reverse direction based on the phase difference between the pulse signals (Δ) and ([3), and the driver 1 rotates in the normal direction and the positive phase of the pulse signal (Δ) advances. Then, this pulse signal is outputted to the up/down counter 9 as an up signal, and when the phase of the pulse signal (B) is advanced due to the reverse rotation of the driver 1, it is outputted to the counter 9 as a down signal.

The up/down counter counts the number of pulses of these up and down signals and performs addition and detraction. The comparator 11 is connected to the output X of the counter 9 and the latch 10
Compare the pulse callan 1 to viY inputted in
Only when X>Y, a differential pulse is output to the latch pulse generator 12. The latch pulse generator 12 is connected to the output of the direction discriminator 8 via an OR circuit 13, and when a pulse from the comparator 11 is input, it outputs this pulse as an operation timing pulse to the latch 10. Therefore, the latch 1o has the counter l- of the up/down counter 9.
It operates when the number reaches the maximum and radiates this count number.

The count latched by the latch 10 is input to arithmetic means 14 consisting of a microcomputer. The calculation means 14 calculates the torque in accordance with the number of pulses, drives the drive circuit 15 based on the calculation result, and displays the display 16.
display the torque digitally.

Next, the operation of the torque measuring device of the present invention will be explained.

When the electric screwdriver 1 rotates in the forward direction, the rotating member 6 rotates until it is balanced with the torque, and the pulse 1 encoder 3 rotates at a rotation angle corresponding to 1-lux, as shown in FIG. Two pulse signals (△) and (8) from encoder 3
is revealed. These pulse signals are input to the direction discriminator 8. Since the phase of the pulse signal (A) is advanced, the direction discriminator 8 determines whether the driver 1 rotates in the normal direction,
A pulse that rises with the pulse of the pulse signal (△) is outputted to the up/down counter 9 as an up signal.

The counter 9 sequentially adds pulses of this up signal.

In FIG. 2, the count number X of the counter 9 is three. The comparator 11 compares the count number X(3) of the counter 9 with the force run number 1 to number Y latched by the latch 1o,
Since the callan l−g2Y of latch 10 is 2, =
The output of the 1-amparator 11 becomes H, the latch pulse generator 12 generates a latch pulse, and the count number X(3) of the counter 9 is latched into the latch 10.

Next, when the driver 1 is reversed and pulse signals (Δ) and (B) are output from the pulse encoder 3, the direction discriminator 8 detects the driver 1 because the phase of the pulse signal (B) is advanced. A pulse that rises with the pulse of the pulseless 1 word (B) is output to the up/down counter 9 as a down signal. The counter 9 sequentially subtracts J: from this down signal, and sets the count 1 - the number X to 1. The comparator 11 is the count number of the non-counter 9
Since (1) is smaller than the count number Y(3) of the latch 10, the latch pulse generator 12 does not output a pulse signal, and therefore, the value of the latch 10 is held as is. .

Next, when the driver 1 rotates forward at a maximum of 1-lux and the pulse encoder 3 outputs pulse signals (A) and (B) with the maximum number of pulses, the phase of the pulse signal (A) is advanced again. Therefore, the direction discriminator 8 receives the pulse signal (A)
A pulse that rises at the pulse of 2 is output as an up signal, and the counter 9 sequentially adds up the pulses, and the count number X becomes 4 in J3 in FIG. Therefore, comparator 11 inputs count number X(4) of counter 9 to count number Y(3) of latch 10, so
latches the count F(X(4)) of the counter 9.

As a result, only the maximum value of the count number of the counter 9, that is, the count number corresponding to the maximum value of 1 to f of the driver 1, is wrapped in the latch 1o.
4 drives the drive circuit 15 based on the maximum count latched in the latch 1o, and causes the display 16 to digitally display the maximum torque of the driver 1.

In the above embodiment, a microcomputer is used as the calculation means 14, but a logic circuit may also be used. However, logic circuits have fixed calculations. That is, in the j8 case of a microcomputer, it is possible to perform calculations by changing the scale to match the power tool of -4 in measurement, but it is not possible to change the scale in the J-Chirac circuit. Although only the elements necessary to explain the principle are shown in the circuit example, it is natural that a sequence control circuit and the like would be included in an actual device.

It goes without saying that the device of the present invention can also be used to measure the 1-lux of a nut trunker in addition to an electric screwdriver.

According to Kimitsuaki, Torque Dohei TF! The analog rotation angle is converted into a pulse signal by a pulse encoder through a rotation member that rotates up to 1. Torque can be measured without generating a charge unlike a hold circuit and without making the detection mechanism more than one. Therefore, an inexpensive torque measuring device capable of accurately indicating torque is required. In addition, since it uses a conventional analog detecting element such as a one-herc measuring device and requires four steps, there is no need to take snow into account at all during installation, making the assembly of the one-herc measurement device extremely easy.

By the way, if you remove the trigger from the pulse encoder and rotate the pulse encoder freely, you can find out the rotational speed of the power tool to be measured by calculating the number of pulses within the 111-hour period. It can also be used as a rotation speed measuring device.

[Brief explanation of the drawing]

Figures 1 (a) and (IJ) are an explanatory diagram and a circuit diagram of the main parts of a 1-herk measuring device that is one of the systems in Komei, and Figure 2 is a diagram for explaining the operation of the device in Figure 1. Time chart i~. 1... Electric driver, 3... Pulse encoder, 4... Pulley, 5... Helical spring, 6... Rotating member , 7...Digital peak hold circuit, 8...
... Direction discriminator, 9 ... Uptown counter, 10 ...
・Latch, 11...Comparator, 12...Latch pulse generator, 14...
- Crushing means, 16... Indicator. Applicant: Nippon Electric Co., Ltd. 1 Agent: Patent attorney 1) Takedai

Claims (1)

[Claims] 1. A rotating member that rotates until it is balanced with the torque of the electric tool to be measured; converting the analog rotation angle of the rotating member into two pulse signals; and converting each pulse signal into two pulse signals. a pulse encoder that outputs a phase difference corresponding to normal rotation and reverse rotation of the power tool; and a pulse encoder that determines whether the power tool is running in the normal rotation or reverse rotation from the phase difference between the respective pulse signals, and outputs the pulse signal when the power tool rotates in the normal direction; A direction discrimination circuit that outputs the pulse signal as a down signal during reverse rotation as an up signal, an up/down counter that adds pulses with the up signal from the circuit and subtracts pulses with the down signal, and a pulse count number of the up/down counter. a digital peak hold circuit including a comparator that controls a latch circuit only when hx reaches a maximum value, and causes the latch circuit to latch the maximum pulse count of the up/down counter; and a maximum pulse count hx from the latch circuit. a calculation means for calculating the torque of the power tool and outputting the result to the total result device;
I.